From a1084e0c0922bd5419629b460424b5a32328099f Mon Sep 17 00:00:00 2001
From: artemp <artem@mapnik.org>
Date: Wed, 22 Mar 2017 14:40:07 +0000
Subject: [PATCH] port GeoJSON parser/generator logic from master

---
 .../json/geometry_generator_grammar_impl.hpp  | 18 ++++----
 include/mapnik/json/geometry_util.hpp         | 43 +++++++++++++------
 2 files changed, 37 insertions(+), 24 deletions(-)

diff --git a/include/mapnik/json/geometry_generator_grammar_impl.hpp b/include/mapnik/json/geometry_generator_grammar_impl.hpp
index 87a60db70..cd4c5d7ef 100644
--- a/include/mapnik/json/geometry_generator_grammar_impl.hpp
+++ b/include/mapnik/json/geometry_generator_grammar_impl.hpp
@@ -56,26 +56,24 @@ geometry_generator_grammar<OutputIterator, Geometry>::geometry_generator_grammar
         ;
 
     geometry_dispatch = eps[_a = geometry_type(_val)] <<
-        (&uint_(geometry::geometry_types::Point)[_1 = _a]
-         << (point | lit("null")))
+        (&uint_(geometry::geometry_types::Point)[_1 = _a] << point)
         |
         (&uint_(geometry::geometry_types::LineString)[_1 = _a]
-         << (linestring | lit("null")))
+         << (linestring | "{\"type\":\"LineString\",\"coordinates\":[]}"))
         |
         (&uint_(geometry::geometry_types::Polygon)[_1 = _a]
-         << (polygon | lit("null")))
+         << (polygon | "{\"type\":\"Polygon\",\"coordinates\":[[]]}"))
         |
         (&uint_(geometry::geometry_types::MultiPoint)[_1 = _a]
-         << (multi_point | lit("null")))
+         << (multi_point | "{\"type\":\"MultiPoint\",\"coordinates\":[]}"))
         |
         (&uint_(geometry::geometry_types::MultiLineString)[_1 = _a]
-         << (multi_linestring | lit("null")))
+         << (multi_linestring | "{\"type\":\"MultiLineString\",\"coordinates\":[[]]}"))
         |
         (&uint_(geometry::geometry_types::MultiPolygon)[_1 = _a]
-         << (multi_polygon | lit("null")))
+         << (multi_polygon | "{\"type\":\"MultiPolygon\",\"coordinates\":[[[]]]}"))
         |
-        (&uint_(geometry::geometry_types::GeometryCollection)[_1 = _a]
-         << (geometry_collection | lit("null")))
+        (&uint_(geometry::geometry_types::GeometryCollection)[_1 = _a] << geometry_collection)
         |
         lit("null")
         ;
@@ -96,7 +94,7 @@ geometry_generator_grammar<OutputIterator, Geometry>::geometry_generator_grammar
         ;
     point_coord = lit('[') << coordinate << lit(',') << coordinate  << lit(']')
         ;
-    linestring_coord = point_coord % lit(',')
+    linestring_coord = (point_coord % lit(','))
         ;
     polygon_coord = lit('[') << exterior_ring_coord << lit(']') << interior_ring_coord
         ;
diff --git a/include/mapnik/json/geometry_util.hpp b/include/mapnik/json/geometry_util.hpp
index cf538ae73..ac5786f4a 100644
--- a/include/mapnik/json/geometry_util.hpp
+++ b/include/mapnik/json/geometry_util.hpp
@@ -43,7 +43,10 @@ struct create_point
     }
 
     template <typename T>
-    void operator()(T const&) const {} // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
     Geometry & geom_;
 };
 
@@ -55,21 +58,21 @@ struct create_linestring
 
     void operator() (positions const& ring) const
     {
+        mapnik::geometry::line_string<double> line;
         std::size_t size = ring.size();
-        if (size > 1)
+        line.reserve(size);
+        for (auto && pt : ring)
         {
-            mapnik::geometry::line_string<double> line;
-            line.reserve(size);
-            for (auto && pt : ring)
-            {
-                line.emplace_back(std::move(pt));
-            }
-            geom_ = std::move(line);
+            line.emplace_back(std::move(pt));
         }
+        geom_ = std::move(line);
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -106,7 +109,10 @@ struct create_polygon
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -130,7 +136,10 @@ struct create_multipoint
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -160,7 +169,10 @@ struct create_multilinestring
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };
@@ -201,7 +213,10 @@ struct create_multipolygon
     }
 
     template <typename T>
-    void operator()(T const&) const {}  // no-op - shouldn't get here
+    void operator()(T const&) const
+    {
+        throw std::runtime_error("Failed to parse geojson geometry");
+    }
 
     Geometry & geom_;
 };